i havnt used a cooling system in a long time. I always hear people using distilled water. all car antifreeze does is lowers the freeze point and raises the boil point, doesnt really make it cool any better. Water is a better heat conductor than anti freeze, thats why you have to mix it. My first water cooler back in the athlon slot days.... my reservoir was my 100 gallon fish tank lol. i used that for a long time, eventually my fish died, but they lived a long time, all i had were a few 8 inch long oscars. so after they died,, i stepped it up a bit.. if i was doind some hardcore gaming, i would just dump some ice in the fishtank